Answer to Question #143992 in General Chemistry for gia

Question

The following equilibrium constants have been determined for hydrogen sulfide at 25 degree C:
H2S (aq) <=> H^+(aq) + HS^- (aq) ; K'c = 9.510^(-8)
HS^- (aq) <=> H^+ (aq) + S^(2-) (aq) ; K''c = 1.010^(-19)
Calculate the equilibrium constant for the following reaction at the same temperature:
H2S (aq) <=> 2 H^+ (aq) + S^(2-) (aq)

Answer 1

H₂S <=> H⁺ + HS^- K'c = 9.5 ×10^-8. ... 1

HS^- <=> H⁺ + S^2- K"c = 1.0×10^-19 ...2

Add 1 and 2

H₂S <=> 2H⁺ + S^2-

K"'c = 9.5×10^-8 × 1.0×10^-19

K"'c = 9.5 ×10^-27